Field of the Invention
The present invention relates to a fine metal mask and a method of manufacturing the same.
Description of the Related Art
In display devices, an organic light emitting diode (OLED) display offers the advantages of a wide viewing angle, excellent contrast and fast response speed. In such an OLED display, several subpixels form a pixel. In a process of manufacturing an OLED display, each subpixel may be formed by several methods, and one method thereof is a deposition method.
In order to form a subpixel using a deposition method, a fine metal mask (FMM) having the same pattern as that of a thin film to be formed is aligned on a substrate. In the fine metal mask, penetration portions are formed corresponding to a pattern. By depositing an organic material on a substrate with such a fine metal mask, a thin film of a desired pattern is formed.
In conventional methods of manufacturing a fine metal mask, the penetration portions that make up the desired pattern have generally been prepared by individually etching a first surface of a base member and a second surface of the base member, the second surface being opposite to the first surface, allowing holes etched in the first surface to communicate with holes etched in the second surface. In a conventional fine metal mask that is produced by such a method, an unwanted lip, or curb, may remain on the inside of the penetration portion opening in the base member. Such a protruding curb may undesirably impact the shapes of the deposited areas of organic film. Because the angle of deposition may vary when the fine metal mask is used to form organic thin films, protruding curbs within the openings in the fine metal mask may reduce the sharpness with which the edges of the films are deposited. Furthermore, in its location on the inside of the penetration portion of the metal mask, the curb may be difficult to remove.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known to a person of ordinary skill in the art.